Calcium signaling-induced Smad3 nuclear accumulation induces acetylcholinesterase transcription in apoptotic HeLa cells

Cell Mol Life Sci. 2009 Jul;66(13):2181-93. doi: 10.1007/s00018-009-0037-z. Epub 2009 May 26.

Abstract

Recently, acetylcholinesterase (AChE) has been studied as an important apoptosis regulator. We previously showed that cellular calcium mobilization upregulated AChE expression by modulating promoter activity and mRNA stability. In this study, we have identified a potential Smad3/4 binding element, TGCCAGACA, located within the -601 to -571 bp fragment of the AChE promoter, as an important calcium response motif. Smad2/3 and Smad4 were shown to bind this element. Overexpression of human Smad3 increased AChE transcription activity in a dose-dependent manner in HeLa cells, whereas dominant-negative Smad3 blocked this activation. Upon A23187 and thapsigargin treatment, nuclear Smad3 accumulation was observed, an effect that was blocked by the intracellular Ca(2+) chelator BAPTA-AM. Calcium-induced AChE transcriptional activation was significantly blocked when the nuclear localization signal of Smad3 was destroyed. Taken together, our data suggest Smad3 can regulate AChE transcriptional activation following calcium-induced nuclear accumulation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acetylcholinesterase / genetics*
  • Acetylcholinesterase / metabolism
  • Animals
  • Apoptosis / physiology*
  • Calcium / metabolism
  • Calcium Signaling / physiology*
  • Cell Nucleus / metabolism*
  • Enzyme Inhibitors / metabolism
  • Gene Expression Regulation, Enzymologic*
  • HeLa Cells
  • Humans
  • Promoter Regions, Genetic
  • Smad2 Protein / metabolism
  • Smad3 Protein / genetics
  • Smad3 Protein / metabolism*
  • Smad4 Protein / metabolism
  • Thapsigargin / metabolism
  • Transcription, Genetic*

Substances

  • Enzyme Inhibitors
  • SMAD2 protein, human
  • Smad2 Protein
  • Smad3 Protein
  • Smad4 Protein
  • Thapsigargin
  • Acetylcholinesterase
  • Calcium